had bought是什么时态

　　That was why he had bought the papers with all his money.

　　这就是他用所有的钱买报纸的原因。

　　When Edward came home, his father asked what books he had bought.

　　爱德华回家后,他父亲问他买了什么书。

　　The judge asked," Then how do you weigh the butter? "The farmer replied," Before the baker started buying butter from me, I had bought bread from him.

　　法官问："那你怎么称黄油的重量?农夫回答说："在面包师开始向我买黄油之前,我已经向他买了面包。"。

　　Harry had carefully bought and wrapped presents for Mark to give them

　　哈里精心购置了礼物又仔细包好，让马克交给他们。